A series of sodium bis(2-ethylhexyl) sulfosuccinate (AOT) analogue surfactants [sodium dibutyl sulfosuccinate (DBSS), sodium dipentyl sulfosuccinate (DPSS), sodium dihexyl sulfosuccinate (DHSS), and sodium dioctyl sulfosuccinate (DOSS)] were synthesized and characterized with 1H NMR and elemental analysis. The solubilities of surfactants in supercritical CO2 (scCO2) and supercritical 1,1,1,2-tetrafluoroethane (HFC-134a) fluids at a temperature range from (308 to 338) K and under pressures of (10 to 30) MPa were measured using a static method coupled with gravimetric analysis. The solubilities of these surfactants are much higher in HFC-134a fluid as compared with that in scCO2. The solubilities increased with increasing temperature and pressure for both scCO2 and HFC-134a fluids. The solubilities in scCO2 increased with increasing carbon atom number of surfactant, whereas they decreased with increasing carbon atom number of surfactant in HFC-134a. The density of scCO2 was simulated with the Peng-Robinson (P-R) equation. The experimental data were used to validate the accuracy of the P-R equation.

A series of Aerosol-OT (AOT, sodium bis(2-ethylhexyl)sulfosuccinate) analogue fluorinated surfactants, i.e.,the sodium salt of bis(2,2,3,3,3-pentafluoropropyl) 2-sulfosuccinate (di-CF2), the sodium salt of bis(2,2,3,4,4,4-hexafluorobutyl)2-sulfosuccinate (di-HCF3), the sodium salt of bis(3,3,4,4,5,5,6,6,6-nonafluorohexyl)2-sulfosuccinate (di-HCF4), and the sodium salt of bis(2,2,3,3-tetrafluoropropyl) 2-sulfosuccinate (di-HCF2), were synthesized and characterized by 1H NMR, 13C NMR, 19F NMR, melting point, and elemental analysis. The pressure-temperature (P-T) phase diagrams for water-in-CO2 (W/CO2) and water-in-1,1,1,2-tetrafluoroethane (W/HFC-134a) microemulsions stabilized by the surfactants were determined. In this work, the phase behaviors for different surfactants are obtained in supercritical CO2 (scCO2) and 1,1,1,2-tetrafluoroethane (HFC-134a) as a function of temperature, pressure, and water-to-surfactant ratio. At a fixed temperature, the cloud-point pressures increased with the increase of water-to-surfactant ratio (Wo) and the concentration of the surfactants. The cloud-point pressures for the surfactants in HFC-134a decrease with an increase in temperature at a fixed Wo and a surfactant concentration, which is in opposition to the results obtained in scCO2.

Dyeing of ramie fiber with C.I. disperse red 74 (DR74) at the temperatures from 343.15 to 403.15 K and under the pressures of 12-20 MPa has been thoroughly investigated using supercritical carbon dioxide (scCO2)as a solvent. Ramie fiber was first treated with alkali and then with benzoyl chloride to improve the affinity and interaction between disperse dye and ramie fiber. The morphological and structure transformations in fiber induced by pretreatment were determined by a Fourier transform infrared spectrometer (FT-IR),X-ray diffraction (XRD),scanning electro-microscopy (SEM),differential scanning calorimetry(DSC),and thermogravimetry analysis (TGA).The modification of ramie fiber with benzoyl chloride was characterized by a degree of substitution (DS).The damage to ramie fiber caused by pretreatment and scCO2 dyeing was determined by stress-strain measurements. The color strength of the fiber was evaluated by K/S measurements. The dyeing effects have been studied by means of time, pressure,temperature,and concentration of dye.

用Benson 基团贡献法计算了碳酸二甲酯(DMC) 的标准摩尔生成焓Δf H0m 、标准摩尔生成吉布斯自由能Δf Gθm 和等压摩尔热容Cp ,m 。计算了不同温度和压力条件下二甲醚(DME) 氧化羰化合成DMC 及DME 与CO2 反应合成DMC 的焓变ΔrHm 、吉布斯自由能变ΔrGm 和平衡常数ln Kθ。计算结果表明:在300～1000 K 的温度及011～30MPa 的压力条件下,由DME 氧化羰化合成DMC 是热力学上可自发进行的反应,而由DME 和CO2 合成DMC 是非自发进行的,需要通过耦合等方式来改变反应途径(或重构反应体系) ,该反应才有可能进行。为由DME 合成DMC 的反应途径设计和催化剂的探索研究提供了热力学依据。

综述了苎麻纤维的改性原理以及苎麻纤维碱法、液氨、烷基化、磺化、氰乙基化、离子液体、阳离子、纳米粒子等改性工艺的最新进展，探讨了超临界流体苎麻纤维的改性。